Exhaust gas sensors are typically used in motor vehicles to measure constituents in the exhaust gas produced by the engine. The exhaust gas may contain hydrocarbons, carbon monoxide, nitrogen oxides (NOx), oxygen and other gases. Measurements from the exhaust gas sensors aid in adjusting the operating parameters of the vehicle, such as the operating parameters that reduce hydrocarbon emissions and improve fuel economy. Diagnostic modules may be employed by the vehicle diagnostic system to ensure proper functioning of the exhaust gas sensors.